Nowadays, there are many kinds of car locks in use and on market, which have almost the same principle that the lock is hooked on the steering wheel, extending out of it for preventing the steering wheel from rotating. Most of them have two sections combined together, and the hooks for engaging with the steering wheel is U-shaped (U.S. Pat. No. 4,738,127), Y-shaped (U.S. Pat. No. 4,887,443), helically shaped (U.S. Pat. No. 4,747,279), etc, and the dimension, length or manipulating method of them are rarely developed (U.S. patent application Ser. No. 01/459,646). So common car locks in use today are considered to have the following disadvantages.
1. To mount a car lock on the steering wheel, the extensible rod should be rotated to align the hook thereon with that on the lock handle.
2. The whole length of a car lock cannot be shortened as desirable, as the hook on the extensible rod is provided at its free end, impossible to be shrunk wholly in the lock handle.
3. The structure of the extensible rod makes its cost high, and the time for manufacture long, as it has a section of annular grooves to be stuck in by the dead bolt of the lock after it is rotated in the lock handle adjusting the whole length of the car lock in mounting it on the steering wheel.